The invention relates to a formwork system comprising formwork elements which have mutually oppositely disposed formwork inner surfaces and can be connected to one another spaced apart from one another by means of formwork ties, wherein a formwork tie consists of a bolt element and two locking elements which, in the two mutually remote end regions of the bolt element, can be coupled to it and are formed for the transmission of tensile forces from the formwork elements onto the bolt element.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Formwork systems of this type are known in various embodiments from the prior art. They are used on construction sites of the most varied sizes in order, in the erection of reinforced concrete carcasses, to define volumes bounded by formwork areas or by an internal and an external formwork which are subsequently filled with liquid concrete. After the concrete has solidified, the formwork elements are then removed again, whereupon they can be reused as a rule for the assembly of further formworks.
Walls, columns, foundations, shafts and the like can be produced from concrete and reinforced concrete, for example, with the formwork systems.
With formwork systems, it is customary to couple the formwork elements forming the inner formwork to the formwork elements forming the outer formwork via formwork ties which are guided through tie holes present in the formwork elements and are connected to the formwork elements such that the internal formwork and the external formwork cannot move apart on the pouring in of concrete. To prevent such a movement, a formwork tie is formed by a bolt element and two locking elements, with the latter, as already mentioned, being suitable for the transmission of tensile forces from the formwork elements onto the bolt element.
The fact is disadvantageous with the known formwork systems that the previously used formwork ties are, as a rule, not able to prevent formwork elements of the internal formwork and of the external formwork from moving toward one another due to a corresponding force action, in particular on the pouring in of concrete, so that a wall ultimately to be produced does not have the desired thickness in all regions after completion.